<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>clip-path</title>
  <style>
    * {
        margin: 0;
        padding: 0;
        box-sizing: border-box;
    }
    ul,
    ol {
        list-style: none;
    }
    .nav {
        width: 200px;
        height: 60px;
        background-color: #141e37;
        margin: 100px;
        text-align: center;
        line-height: 60px;
        color: #fff;
        font-size: 16px;
        -webkit-clip-path: polygon(50% 0%, 0% 100%, 100% 100%);
        clip-path: polygon(50% 0%, 0% 100%, 100% 100%);
    }
    .box {
        position: relative;
    }
    .box img {
        position: absolute;
        top: 0;
        left: 0;
        width: 700px;
        transition: all 2s;
    }
    .box img:nth-child(2) {
        -webkit-clip-path: polygon(0% 0%, 0 0, 0 53%, 0% 100%, 0 100%);
        clip-path: polygon(0% 0%, 0 0, 0 53%, 0% 100%, 0 100%);
    }
    .box:hover img:nth-child(2) {
        -webkit-clip-path: polygon(0% 0%, 75% 0%, 100% 50%, 75% 100%, 0% 100%);
        clip-path: polygon(0% 0%, 75% 0%, 100% 50%, 75% 100%, 0% 100%);
    }
  </style>
</head>
<body>
  <div class="nav">123</div>
  <div class="box">
    <img src="./img/blue.png" alt="">
    <img src="./img/orange.png" alt="">
  </div>
</body>
</html>